Experimental and Numerical Investigation for Quench Annealed 316L Stainless Steel by Number of Quenching Media

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1 IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) e-issn: ,p-ISSN: X, Volume 14, Issue 2 Ver. V (Mar. - Apr. 2017), PP Experimental and Numerical Investigation for Quench Annealed 316L Stainless Steel by Number of Quenching Media Payman Sahbah Ahmed 1, and SirwanSarbast Talabani 2 1,2 Manufacturing Engineering Department, Koya University, Koysinjaq, Kurdistan, Iraq Abstract: The aim of this research is to study the effect of using a number of quechants for quench annealing on some mechanical properties of 316L stainless steel.a solid model of the specimen is created and a finite element analysis (FEA) by solidworks is conducted using the ASTM standard as a guide. Experimental bending test shows that the best quenching media is water which gives the highest modulus and apricot juice was the lowest. The highest von mises values for all quenching media for the three loading types are below the yield strength demonstrating that they pass the von Mises stress failure criteria by successfully withstanding the applied loads. Quenching by apricot juice gives the highest displacement values while water gives the lowest displacement value.both experimental and numerical investigation show that quenching by water is the best quenching medium for quench annealing of 316L stainless steel. Keywords: 316L stainless steel, quench annealing, solution annealing, solidworks, FEM analysis. I. Introduction Corrosion is the main problem in iron and its alloys when they used in air, acids and in furnaces at elevated temperatures. Corrosion problem in Iron could be solved by adding chromium and nickel to give iron alloy known as stainless steel which have better corrosion resistance at elevated temperatures of 1100⁰C, do not corrode in sea water and have good corrosion resistance to acids with high concentrations. Stainless steel is the best choice for any designer because of its distinctive global utility and fabrication properties which make it the main industrial structural material such as cold rolled sheets, oil and gas, chemical processes and food industries.good corrosion resistance, manufacturing and weldability can be obtained by using the austenitic stainless steel. Their main usage is in cryogenic applications due to their good impact strength at low temperatures. Existence of molybdenum in austenitic stainless steel gives 316 type which is the second main type in production after 304 and have better and preferable properties than 304 especially better pitting and crevice corrosion resistance in chloride. Decreasing the carbon content of 316 gives 316L type which have high resistance to precipitation of carbides on grain boundaries i.e. sensitization, high toughness at normal and cryogenic conditions, higher creep, stress to rupture and tensile strength at high temperatures [1]. Heat treatment should be done on the austenitic stainless steels during or after manufacturing to remove the effects of cold forming or to dissolve precipitated chromium carbides resulting from thermal exposures. The most important heat treatment for 316 stainless steel alloys is the solution anneal which is done by heating in temperature range of (1040 to 1175 C) then air cooling or a water quench (called solution-annealing or quench annealing [2], depending on section thickness. Cooling should be sufficiently rapid through the ( C) range to avoid re-precipitation of chromium carbides and provide optimum corrosion resistance. Cooling should be in less than three minutes [3]. water, aqueous solutions of salts and alkalis, and oils are the main liquids commonly used as rapid cooling or quenching media and they subject to boiling in three stages as follows: 1. Stage one: film boiling stage, the cooling rate is low in this stage in which a vapor blanket is formed on the surface of the steel. 2. Stage two: boiling with the formation of bubbles begins when the vapor film is completely broken up. The highest rate of cooling is in this stage. It is observed in cooling the surface to a temperature below the critical. It is also called the stage of nucleate boiling, or the vapor-transport stage. 3. Stage three: heat exchange by convection at temperatures below the boiling point of the quenching medium, the cooling rate is lowest. This is often called the liquid stage [4]. The aim of this research is to study the effect of using number of quechants for the solution annealing or quench annealing on some mechanical properties of 316L stainless steel. A solid model of the specimen is created and a finite element analysis (FEA) by solidworks is conducted using the ASTM standard as a guide. The FEA model will help to predict failure locations. II. Materials and Methods The research has been carried out on the commercial stainless steel alloy 316L. The chemical composition of the alloy is indicated in Table 1 [5]. The influence of solution annealing on bending properties and microstructure of 316L alloy after quenching, tempering and chilling was investigated and compared with DOI: / Page

2 as received specimen. Details of quenchants and heat treatments [2] are listed in table 2. Solution annealing treatment is done for bending specimen [6]. To revel the microstructure of 316L stainless steel Kalling s No. 2 etchants is used which consist of 5g CuCl2, 100ml hydrochloric acid and 100ml ethanol [7] Table 1 Chemical composition of 316L stainless steel [5]. C Mn P S Si Cr Ni Mo N Fe Balanced Table 2: Steps of 316L Stainless Steel Solution or Quench Annealing heat treatments. Quenching Temperature Soaking Time Quenching Medium notes Chilling Temperature Chilling Time 1050⁰C 11.5 min Water Distilled -17⁰C 48 hr Water Distilled Without chilling Coffee 10gm Coffee:1000ml Water Without chilling Apricot Juice 10gm Apricot:1000ml Water Without chilling III. Modelling The software used for modelling is Solid Works and the steps of modelling and simulation is as follows: starting with giving information about the sample such as: mass, volume, density and weight, then properties of study should be defined such as analysis type and mesh type, followed by specifying the unit system which is SI for this research. Materials properties of the research specimens should be defined such as: yield strength, tensile strength, elastic modulus, Poisson s ratio, mass density and coefficient of thermal expansion. Loads and fixtures should be defined where three types of fixtures and loads are used in this study the first and second types for bending test, the first type samples are free from the x and z-directions but restricted from the y-direction at the ends and a force is subjected on the middle of the sample as shown in Fig.1, six force values are used for this study: 100, 200, 300, 400, 500 and 600 N to resemble experimental bending test. Problem of samples crawling has appeared in this type of loading, to avoid crawling problem, samples are fixed from all directions at the ends and a force is subjected on the middle in the second type as shown in Fig.2, also six force values are used for this type: 100, 200, 300, 400, 500 and 600N. Third type of loading the samples are fixed from one end and a tensile force is subjected from the other end as shown in Fig.3, six force values are used in this type of loading: 100, 200, 300, 400, 500 and 600N. The last step of modelling is defining mesh information such as: mesh type, element size and mesh quality, Fig.4 shows sample after meshing. Dimensions of the sample are: 95 mm Length, 12 mm width and 2.5 mm thickness. Fig.1 Loading and Fixture type I: samples are free from the x and z-directions but restricted from the y-direction at the ends and a force is subjected on the middle. Fig.2 Loading and Fixture type II: fixed from the ends and force on the middle of the sample. DOI: / Page

3 Fig.3 Loading and Fixture type III: fixed from one end and a force on the other end of the sample. Fig.4 Sample after meshing. IV. Results and Discussion 4.1. Experimental Results Solution heat treatment results and effect of quenching media are illustrated in Fig.5 where it can be seen that the best quenching media is water which gives the highest modulus followed by coffee, chilled, as received respectively and apricot juice was the worst, this is because of the fact that water showed the three required stages of cooling as mentioned in the introduction, and this can be evidenced by the resultant phases as can be seen in Fig.6, where the precipitation of the carbides on the boundaries of austenite is obvious which lead to increase bending properties, while other media did not show the same scenario where chilling and the presence of coffee particles lead to increase the precipitation of carbides and apricot has suppressed the formation of the carbides which resulted in decreasing the bending properties. Fig.5 Comparison of bending modulus values for different quenching media. DOI: / Page

4 As received Water Chilled Coffee Apricot Juice Fig.6 Microstructure image of 316L stainless steel in different quenching media (400X) Modelling Results Loading and Fixture type I Results The von Mises stresses are analyzed through the contour plots which were displayed from the results of the finite element analysis performed in SolidWorks for each of the models. The von mises stresses are displayed through the contour plots below in Fig.7, red color in the middle of the sample shows the highest von mises values where all quenching media show a von mises values below the yield strength demonstrating that they pass the von Mises stressfailure criteria by successfully withstanding the applied loads. Fig.8 shows von mises values for different quenching media where it can be seen that quenching by coffee gives the highest von mises values followed by water, chilled as received and apricot juice. Fig.7 Von Mises Stress Contour Plot of Coffee (Loading and Fixture Type I) DOI: / Page

5 Fig.8 Von Mises Stress Values for different quenching Media (Loading Condition I). The displacement is analyzed through its components, displacement is caused by the bending loads occurring through the model and has been shown in Fig.9. Maximum displacement values are at the ends in the case of as received, chilled and apricot juice while maximum displacement values are in the middle for water and coffee quenching media, this is because of loading condition of free ends in addition to higher bending modulus values in case of water and coffee compared with as received, chilled and apricot juice quenching media. Fig.9 Displacement Contour Plot of Apricot Juice (Loading and Fixture Type I) Fig.10 shows displacement values for different quenching media where it can be seen that quenching by apricot juice gives the highest displacement values followed by as received, coffee, chilled and water gives the lowest displacement value. Fig.10 Displacement Values for different quenching Media (Loading Condition I). DOI: / Page

6 Loading and Fixture type II Results The von mises stresses for the type II of loading and fixture are displayed through the contour plots below in Fig.11, red color in the middle of the sample is very small area which shows the role of the fixation in this type of loading which results in decreasing the values of stresses resulted in this samples, the highest von mises values in all quenching media shows a von mises values below the yield strength demonstrating that they pass the von Mises stress failure criteria by successfully withstanding the applied loads. Fig.12 shows von mises values for different quenching media where it can be seen that quenching by coffee gives the highest von mises values followed by water, apricot juice, chilled and as received. Fig.11 Von Mises Stress Contour Plot of Coffee (Loading and Fixture Type II) Fig.12 Von Mises Stress Values for different quenching Media (Loading Condition II). Fig.13 shows displacement contours for all quenching media where it can be seen that the maximum values are in the middle and the lowest displacement values are in the fixed ends in all quenching media. Fig.13 Displacement Contour Plot of Apricot Juice (Loading and Fixture Type II) DOI: / Page

7 Fig.14 shows displacement values for different quenching media where it can be seen that quenching by apricot juice gives the highest displacement values followed by as received, coffee, chilled and water gives the lowest displacement value. Fig.14 Displacement Values for different quenching Media (Loading Condition II) Loading and Fixture type III Results The von mises stresses are displayed through the contour plots below in Fig.15, red color (which cover very small area) in the end of the sample shows the highest von mises values where all quenching media are below the yield strength demonstrating that they pass the von Mises stress failure criteria by successfully withstanding the applied loads. Fig.16 shows von mises values for different quenching media where it can be seen that quenching by coffee gives the highest von mises values followed by chilled, apricot juice, as received and water. Fig.15 Von Mises Stress Contour Plot of Coffee (Loading and Fixture Type III) Fig.16 von Mises Stress Values for different quenching Media (Loading Condition III). The displacement is analyzed through its components, displacement is caused by the tension loads occurring through the model and has been shown in Fig.17. Maximum displacement values are at the end where the tension force is subjected for all quenching media. DOI: / Page

8 Fig.17 Displacement Contour Plots of Apricot Juice (Loading and Fixture Type III) Fig.18 shows displacement values for different quenching media where it can be seen that quenching by apricot juice gives the highest displacement values followed by as received, chilled, coffee and water gives the lowest displacement value, this is because of higher tensile modulus values in case of water and coffee compared with as received, chilled and apricot juice quenching media. Fig.18 Displacement Values for different quenching Media (Loading Condition III). V. Conclusions 1. Experimental bending test shows that the best quenching media is water which gives the highest modulus followed by coffee, chilled, as received respectively and apricot juice was the worst. 2. The highest von mises values for all quenching media for the three loading types are below the yield strength demonstrating that they pass the von Mises stress failure criteria by successfully withstanding the applied loads. 3. Quenching by apricot juice gives the highest displacement values while water gives the lowest displacement value. 4. Both experimental and numerical investigation show that quenching by water is the best quenching medium for quench annealing of 316L stainless steel. References [1] Internet: [2] W. A. Hanna, L. Q. Abbas, M. A. Najm: Study of polymer quenchants effect on some properties of stainless steel alloy (316l), Journal of Engineering and Technology, Vol.27, No.10, pp , (2009). [3] Internet,Types 316 (S31600), 316L (S31603), 317 (S31700), 317L (S31703), [4] Yu. M. Lakhtin: Engineering physical metallurgy and heat treatment, Mir Publishers, pp , (1983). [5] ASTM A240: Standard specification for, chromium and chromium-nickel stainless steel plate, sheet, and strip for pressure vessels and for general applications, March x, (2009). [6] ASTM E290-09: Standard test method for bending testing of material for ductility, (2009). [7] R. CheraGhali, Sh. Moradi, M. Ghoranneviss, P. Aberomand Azar and S.A. Khorrami, Etching of 316l stainless steel by different chemical etchant solutions for the growth of carbon nanotubes by thermal chemical vapor deposition, Asian Journal of Chemistry; Vol. 23, No.7, pp , (2011). DOI: / Page